Abstract
A technique has been developed that enables remote sensing of the temperatures of liquid drops in a medium of an immiscible, transparent liquid with the aid of dispersing microcapsules of thermochromic liquid crystal in each drop under illumination by either a planar floodlight or a light sheet which cuts the drop at a meridian. Based on appropriate hue-temperature calibrations made with an isothermal, stationary drop/medium system, one can analyze spatial and time variations of temperature within drops in motion under transient convective heating (or cooling) from the medium.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
Abbreviations
- B :
-
tristimulus blue component
- D :
-
drop diameter
- G :
-
tristimulus green component
- H :
-
hue angle
- h 0 :
-
constant term in the expression for H
- H m :
-
mean value of H over drop surface
- h :
-
vertical coordinate fixed onto test column
- R :
-
tristimulus red component
- Re :
-
drop Reynolds number, UD/v c
- r, g, b :
-
chromaticity coordinates
- r :
-
drop radius
- s :
-
penetration depth of light into drop
- T :
-
temperature
- T d :
-
instantaneous drop temperature
- T d0:
-
initial drop temperature
- T c :
-
continuous-phase temperature
- U :
-
velocity of rise of drop
- z :
-
vertical coordinate laid on drop
- v c :
-
kinematic viscosity of continuous phase
- θ :
-
angle of lighting measured from camera axis
- θ s :
-
local view angle (azimuth)
- φ :
-
polar angle
References
Abramzon B; Borde I (1980) Conjugate unsteady heat transfer from a droplet in creeping flow. AIChE J 26: 536–544
Dabiri D; Gharib M (1991) Digital particle image thermometry: the method and implementation. Exp Fluids 11: 77–86
Kaji N; Mori YH; Tochitani Y; Komotori K (1978) Direct-contact heat transfer to drops in an intermittent electric field. Proc 6th Int Heat Transfer Conf., Vol 3: 165–170
Moresco LL; Marschall E (1979) Temperature measurements in a liquid-liquid direct-contact heat exchanger. AIChE Symp Ser 75: 266–272
Rhee HS; Koseff JR; Street RL (1984) Flow visualization of a recirculating flow by rheoscopic liquid and liquid crystal techniques. Exp Fluids 2: 57–64
Wilcox NA; Watson AT; Tatterson GB (1985) Color/temperature calibrations for temperature sensitive tracer particles. Proc Int Symp on Physical Flow Visualization, Albuquerque, N.M., 65–74
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Nozaki, T., Mochizuki, T., Kaji, N. et al. Application of liquid-crystal thermometry to drop temperature measurements. Experiments in Fluids 18, 137–144 (1995). https://doi.org/10.1007/BF00230257
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00230257